The present invention is directed in general to an optical apparatus, a method of manufacture thereof, and an optical integrated circuit comprising the optical apparatus.
Optical communication devices typically include several discrete active and inactive device components, each performing different functions. Examples of individual device components include optical switches, electro-optic modulators, arrayed waveguide gratings (AWG), waveguide splitters, or optical amplifiers. Such device components are typically fabricated individually using different processes on different substrates. As an example, an AWG is fabricated in a silica substrate, while an electro-optic modulator is fabricated in a lithium niobate substrate.
Heretofore, it has not been practical to fabricate two different optical devices, such as passive and active electro-optic devices, on a single substrate. Typically the waveguide core for an optical device is formed in an inorganic substrate, such as silica, by doping the substrate. For example, the portion of the substrate in which the waveguide is located is doped with a single type of dopant. It has proven difficult to selectively dope discrete portions of silica to form the waveguide cores for different types of devices. Thus, for example, the entire silica wafer may serve as the substrate for forming components of an electro-optic modulator or of an AWG, but not both. Rather than form two different types of optical devices on a single substrate discrete device components are fabricated on separate substrates and then interconnected via optical fibers.
The separate fabrication and interconnection of such discrete device components, however, adds significant manufacturing costs. In particular, the high precision required to properly align interconnecting optical fibers with the discrete devices amounts to a substantial portion of the cost of fabricating the optical device system. Moreover, optical losses where the discrete device components are interconnected, degrade performance of the optical device.
Accordingly, what is needed in the art is an optical apparatus that integrates optical devices capable of meeting the stringent requirements of the optoelectronic industry, while not experiencing the problems associated with previous optical devices.
To address the above-discussed deficiencies, one embodiment of the present invention provides an optical apparatus. The optical apparatus includes a substrate, a first waveguide core formed in the substrate and a second waveguide core. The second waveguide core comprises an organic polymer formed in the substrate and optically coupled to the first waveguide core. The second waveguide core has a different composition than the first waveguide core.
In another embodiment, the invention further provides a method of manufacturing an optical apparatus. The method comprises providing a substrate and forming a first waveguide core in the substrate. The method further includes forming a second waveguide core comprising an organic polymer in the substrate, wherein the second waveguide core is optically coupled to the first waveguide core and has a different composition than the first waveguide core.
Yet another embodiment of the present invention provides an optical integrated circuit. The optical integrated circuit comprises a first optical device and a second optical device. The first optical device includes a first waveguide core formed in a substrate, and the second optical device includes a second waveguide core comprising a polymer formed in the substrate and optically coupled to the first waveguide core and has a different composition than the first waveguide core.